A Trial Comparing the Efficacy and Safety of Anakinra Versus Intravenous Immunoglobulin (IVIG) Retreatment, in Patients With Kawasaki Disease Who Failed to Respond to Initial Standard IVIG Treatment

The patients will receive anakinra, an analogue of the IL-1 receptor antagonist, at a starting dose of 4 mg/kg. If patients are still febrile with 12 hours (H12) of treatment, they will receive a supplementary dose of 2 mg/Kg; otherwise, they will remain at a starting dose of 4 mg/kg. If they are still febrile at H24, they will receive a dose of 8mg/kg; otherwise, they will maintain their dose of 6 mg/kg. Patients with temperature \<38°C at any point between initiation and day 14, but who develop secondary fever due to KD could have further escalation dose of anakinra until a maximum dose of 8mg/Kg. Patients will receive anakinra during 14 days independently of the period of escalation dose if any. After the last escalation dose, if any necessary, the primary criteria will be measured. Patients not responding to anakinra will follow usual standard care and will complete information related to all the study visits

The patients will receive a standard therapy, IVIG infusion of 2g/kg, and their treatment will follow usual standard care. Patients in the IVIG treatment will complete information related to the study visits.